<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body bgcolor="pink">
		<div align="center">
		<h2>简易计算器的制作</h2>
		<form action="calculate.jsp" method="post">
		第一个数:<input type="text" name="s1"><br>
		第二个数:<input type="text" name="s2"><br>
		<!-- select下拉菜单也需要添加name属性 -->
		操作类型:<select name="s3">
		<!-- option也需要添加value属性 -->
			  <option value="+">+</option>
			  <option value="-">-</option>
			  <option value="*">*</option>
			  <option value="/">/</option>
			  </select>&nbsp;&nbsp;&nbsp;
		<input type="submit" value="计算">
		</form>
		</div>
</body>
</html>